Struct Server 

pub struct Server {
    pub backend: Backend,
    /* private fields */
}

MCP server backed by a database backend.

Fields

backend: Backend

The active database backend.

Implementations

impl Server

pub fn new(backend: Backend) -> Self

Creates a new MCP server with the given database backend.

The tool router is built based on the backend’s capabilities and read-only setting. SQLite does not support create_database.

impl Server

pub async fn list_databases(&self) -> Result<CallToolResult, ErrorData>

List all accessible databases on the connected database server.

Errors

Returns ErrorData if the backend query fails.

pub async fn list_tables( &self, req: Parameters<ListTablesRequest>, ) -> Result<CallToolResult, ErrorData>

List all tables in a specific database.

Errors

Returns ErrorData if the backend query fails.

pub async fn get_table_schema( &self, req: Parameters<GetTableSchemaRequest>, ) -> Result<CallToolResult, ErrorData>

Get column definitions for a table.

Errors

Returns ErrorData if the backend query fails.

pub async fn get_table_schema_with_relations( &self, req: Parameters<GetTableSchemaRequest>, ) -> Result<CallToolResult, ErrorData>

Get column definitions plus foreign key relationships.

Errors

Returns ErrorData if the backend query fails.

pub async fn read_query( &self, req: Parameters<QueryRequest>, ) -> Result<CallToolResult, ErrorData>

Execute a read-only SQL query with AST validation.

Always enforces SQL validation (only SELECT, SHOW, DESCRIBE, USE, EXPLAIN allowed) as defence-in-depth, regardless of the server’s read-only setting.

Errors

Returns ErrorData if SQL validation fails or the query errors.

pub async fn write_query( &self, req: Parameters<QueryRequest>, ) -> Result<CallToolResult, ErrorData>

Execute a write SQL query.

No SQL type validation — the tool boundary is the access control. This tool is only registered when the server is not in read-only mode.

Errors

Returns ErrorData if the query fails.

pub async fn create_database( &self, req: Parameters<CreateDatabaseRequest>, ) -> Result<CallToolResult, ErrorData>

Create a new database if it doesn’t exist.

Errors

Returns ErrorData if the backend query fails.

Trait Implementations

impl Clone for Server

fn clone(&self) -> Server

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Server

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl ServerHandler for Server

fn get_info(&self) -> ServerInfo

async fn list_tools( &self, _request: Option<PaginatedRequestParams>, _context: RequestContext<RoleServer>, ) -> Result<ListToolsResult, ErrorData>

async fn call_tool( &self, request: CallToolRequestParams, context: RequestContext<RoleServer>, ) -> Result<CallToolResult, ErrorData>

fn get_tool(&self, name: &str) -> Option<Tool>

Get a tool definition by name.

fn enqueue_task( &self, _request: CallToolRequestParams, _context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<CreateTaskResult, ErrorData>> + Send

fn ping( &self, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<(), ErrorData>> + Send

fn initialize( &self, request: InitializeRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<InitializeResult, ErrorData>> + Send

fn complete( &self, request: CompleteRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<CompleteResult, ErrorData>> + Send

fn set_level( &self, request: SetLevelRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<(), ErrorData>> + Send

fn get_prompt( &self, request: GetPromptRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<GetPromptResult, ErrorData>> + Send

fn list_prompts( &self, request: Option<PaginatedRequestParams>, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<ListPromptsResult, ErrorData>> + Send

fn list_resources( &self, request: Option<PaginatedRequestParams>, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<ListResourcesResult, ErrorData>> + Send

fn list_resource_templates( &self, request: Option<PaginatedRequestParams>, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<ListResourceTemplatesResult, ErrorData>> + Send

fn read_resource( &self, request: ReadResourceRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<ReadResourceResult, ErrorData>> + Send

fn subscribe( &self, request: SubscribeRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<(), ErrorData>> + Send

fn unsubscribe( &self, request: UnsubscribeRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<(), ErrorData>> + Send

fn on_custom_request( &self, request: CustomRequest, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<CustomResult, ErrorData>> + Send

fn on_cancelled( &self, notification: CancelledNotificationParam, context: NotificationContext<RoleServer>, ) -> impl Future<Output = ()> + Send

fn on_progress( &self, notification: ProgressNotificationParam, context: NotificationContext<RoleServer>, ) -> impl Future<Output = ()> + Send

fn on_initialized( &self, context: NotificationContext<RoleServer>, ) -> impl Future<Output = ()> + Send

fn on_roots_list_changed( &self, context: NotificationContext<RoleServer>, ) -> impl Future<Output = ()> + Send

fn on_custom_notification( &self, notification: CustomNotification, context: NotificationContext<RoleServer>, ) -> impl Future<Output = ()> + Send

fn list_tasks( &self, request: Option<PaginatedRequestParams>, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<ListTasksResult, ErrorData>> + Send

fn get_task_info( &self, request: GetTaskInfoParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<GetTaskResult, ErrorData>> + Send

fn get_task_result( &self, request: GetTaskResultParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<GetTaskPayloadResult, ErrorData>> + Send

fn cancel_task( &self, request: CancelTaskParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<CancelTaskResult, ErrorData>> + Send